The Formula For Faster Climbing

To reach the top of Cheyenne Canyon in Colorado Springs in 20 minutes, you have to be able to churn out 4 watts of power for every kilogram of body weight. Garmin-Cervelo's Tom Danielson set the record on this climb in 2006, clocking in at 13:34 (6.7 watts/kg).

The power-to-weight ratio (PWR) is cycling's great leveler. It's a measure that allows a comparison of cyclists' abilities even when the riders vary in size. Take, for instance, two of my coaches, Craig Griffin and Lindsay Hyman, who this spring made a deal to see who could be first to break 20 minutes up the 5-kilometer, 1,200-vertical-foot ascent.

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Griffin is 5-foot-10 and weighs 76kg (167 pounds), and Hyman is 5-foot-3 and weighs 55kg (121 pounds). Both started within 0.4 watts/kg of the target. The key to getting faster is raising your PWR. As more cyclists buy power meters, it's easy to monitor the number. But even if you don't track your watts, you can still raise your PWR just like every other cyclist--by lowering your body weight or raising your average power output, or both.

DO THE MATH To determine your PWR, divide your body weight in pounds by 2.2 to convert it to kilograms, then divide your weight into the average power from a 20- or 30-minute time trial. (PWR isn't a static number, but rather corresponds to a specific time span. A rider who averages 6.8 watts/kg for 30 minutes may only be able to sustain 6.4 watts/kg for an hour.) Example: Griffin's 20-minute TT power is 275 watts, so given his 76kg, his PWR for 20 minutes is 3.6 watts/kg. (Lindsay is at 3.8 watts/kg. Get on it, Craig.) For comparison, an athlete needs to be able to produce 6.8 watt/kg in a 30-minute pre-race test in order have a chance at winning the Tour de France. Beginners or Cat 5s range from 2.5 to 3.2 for men and 2.1 to 2.8 for women; Cat 3 racers typically range 3.7 to 4.4 (men) and 3.2 to 3.8 (women).

THE BEST WAY TO RAISE IT For cyclists who are carrying around more than 10 extra pounds, losing weight and gaining power are equally achievable through good nutrition and focused training. Heavier cyclists have the potential to make bigger improvements because they can attack both parts of the equation. Between the two coaches in my office, this favors Griffin, because Hyman is already very lean. As an example of how small changes can make a big difference, Cheyenne Canyon averages an 8 percent grade for 5 kilometers. If a 75kg rider with a max sustainable power of 250 watts loses 2.5kg, or about five pounds, that would cut 38 seconds off this rider's time. Improving power output by 20 watts without any weight loss cuts 85 seconds. If this rider loses 2.5 kilos and increases power by 20 watts, the improvement jumps to 2:03.

HOW FAR CAN YOU GO? Elite racers aim to be as strong and as light as possible, but this is a delicate balance that can't be maintained for very long. Most experienced cyclists can expect to see a 15 percent variance in PWR during the year. Because it's far easier to make the ratio go down than up, changes greater than 15 percent often indicate that you either gained too much weight or decreased your training load too much during the winter. On the flip side, there are physiological limits to how light you can get while maintaining a high power output.

Here's the test: If you're leaner than you've ever been and your average power output on climbs starts to decline, you've reached the tipping point. Try gaining two or three pounds, and back off your training a little bit. Your power will likely come back up, and from now on you should consider this your minimum allowable weight. Future gains in PWR will need to come from better training. Of course, there's also the weight of your equipment to consider, because shaving grams from your bike will effectively increase your PWR. I discourage athletes from thinking about buying their way to a goal as a real solution, though.

So, who was the first to break 20 minutes up the canyon? Their challenge ended June 1, and I've posted the results on trainright.com. Personally, I think Lindsay's going to take it.